Hi
I've got a problem with your control EjDiagram, specifically with connector constraint: "DragLabel" .
When I add EjDiagram to my connector sometimes my labels are grouped with them.
Additionally I enclose jsplaygroundand video with example of this situation:
http://jsplayground.syncfusion.com/tuf5qm5w
http://screencast.com/t/tdd7FlpFnn